Bump @testing-library/user-event from 7.2.1 to 8.0.3 in /ui

Bumps [@testing-library/user-event](https://github.com/testing-library/user-event) from 7.2.1 to 8.0.3.
- [Release notes](https://github.com/testing-library/user-event/releases)
- [Commits](https://github.com/testing-library/user-event/compare/v7.2.1...v8.0.3)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

ui/package.json

@@ -5,7 +5,7 @@
   "dependencies": {
     "@testing-library/jest-dom": "^5.0.0",
     "@testing-library/react": "^9.3.2",
-    "@testing-library/user-event": "^7.1.2",
+    "@testing-library/user-event": "^8.0.3",
     "jwt-decode": "^2.2.0",
     "prop-types": "^15.7.2",
     "ra-data-json-server": "^3.1.2",